Bug: Checkmate symbol appears on king when it isn't checkmate

Really sorry, I haven't got time to submit a proper issue on GitHub. But take a look at this:  https://lichess.org/J6vA7fsJ/black This happened when just going through some alternative lines after the game.

fixing incoming: https://github.com/lichess-org/lila/pull/21898

@Lou-E problem fixed now :)

@SergioGlorias nice one :)